Another Harris County official spent the day in the grand jury room amid a widening investigation into Precinct 7.

Just a few weeks after the FBI swept out Harris Co. Precinct 1 Constable Jack Abercia in a corruption scandal, now it's Constable May Walker facing trouble.

The Precinct 7 constable didn't testify before the grand jury Tuesday, but spent much of the day trying to hide her face from our camera. Her top aide, Lieutenant Sylvia Trevino, was in the grand jury room all day.

This DA investigation was sparked after 13 Undercover found campaign records in Lt. Trevino's office at Precinct 7 -- evidence the constable used her county staff to solicit campaign funds from employees based on their rank.

Constable Walker has denied wrongdoing.

And she's not the last constable under criminal investigation. Employees from Precinct 6 Constable Victor Trevino's office have been filing into the DA's office and the county auditor. All signs of widening investigations that we are on top of.